Telegraph system



NOV- 3, 1951 E. E..KLE1NSCHM|DT 2,573,718

TELEGRAPH SYSTEM Filed Aug. 28, 1943 4 Sheets-Sheet l /c 2.a' if f/ 2725 2f ff /J Nov. 6, 1951A E. E. KLEINSCHMmT 2,573,718

TELEGRAPH SYSTEM Filed Aug; 28, 1945 4 sheets-sheet 2 27u/ if@ Nov. 6, 1951 l E. E. KLElNscl-:MIDT 2,573,718

TELEGRAPH SYSTEM 1 4 Sheets-Sheet 5 Filed Aug. 28, 1945 Elf 7- //f i if gg/ f5 yf MM Mm N0 6, 1951 E. E. KLEINSCHMIDT 2,573,718

f TELEGRAPH SYSTEM Filed'Aug. 28, 1945 4 sheets-sheet 4 74 E@ *ff f/ /w Y m MMS Patented Nov. 6, 1951 UNITED STATES PATENT O F F ICE 'TELEGRAPH SYSTEM Edward E..Kleinschmidt,'Hghland Park, Ill.

Application August 28, 1943, Serial No. 500,414

17 Claims.

My present invention relates .to telegraph systems and apparatus, and-more particularly to systems and apparatus :for detecting x:faults in the transmission of telegraphmessages.

Y More particularly, my invention `relates to the detection of faults in telegraph message transmission utilizing automatic and manual switching equipment for the reception of messages atrepeating stations 'in perforated tape for other suitable -recording media. which can .be used `in suitable apparatusto automatically re-transmit the messages. A Vfully automatic switching and Aretransmitting system .of this typeis shown inmy Patent No. 2,193,967, in which every message .when received by `.the addressee controls answer back apparatus which automatically lsends a coniirmation message to :thesender to indicate that Ahis message has been properly received. `Some systems in use :at the 'present `time use in part automatic and in part manual switching and check transmission over trunk Lline circuits by automatically adding tsuccessive count numbers to messagesas they are transmitted so 'that lost or mutilated messages maybe traced. An attendant at the receiving' station checks fthese numbers for consecutiveness as well .as for the correct reception of the message. Means `have "also been devised to indicate the 'improper opera.- rtion of trunk circuits .such as may be vcaused by la grounded or an open line.

Since the blank or non-perforating combina--y 'tion is used in standard circuits to 'feed out tape between messages when the l-perforator does not keep up with transmission `as well as during idle time, there are at times quite a number of such combinations present in the tape which in automaticsystems become cumulative and therefore take up considerable line time in their transmission.

s All of such prior methods for safeguarding thc correct transmission of telegraph rnessa-'ges are, however, ineiiicient and complicated, and are 'wasteful of line time. Furthermore, they allrequire a great deal of manual supervision to detect and correct any .faults that Vmay occur, thus interposing undesirable delays in transmission.

In my invention, a checking or test signal is automatically transmitted and received on test instruments which are switched into the circuits ,between messages, without, however, being re corded in :the 'receivedmessage record. If the :signal checks, the succeeding messages are transmitted and, so long v, as "the #received checking 1 signalsjcorrespond with" the "setting of 'the test -instrument at the receiving position, #message transmission continues. If, however, a `received checking signal does notcheck with the settingof the receiving test instrument, or if anyfaultoccurs in the receiving apparatus Vto prevent `the reception of the test or checking signal, or if a blank combination appears in the 'body of `a message, or if the line is opened or grounded, thus preventing the reception of the test or checking signal, the receiving `apparatus is automatically stopped and an `alarm signal is given to the station attendant who thereupon communicates with the sending station to Vcorrect the'fault and 'to re-transmit messages that were transmitted during the .fault interval.

Messages in accordance with my invention are preferably transmitted by positive and'negative or marking and spacing impulses in signal vccmvbinations of the Baudot five unit permutation code.

I preferably use the blank or non-marking or non-perforating combination for a lmessage end signal followed 'by single marking impulses 'for the test signal combinations with 'novel test or checking instruments that ,repeat these signal combination settings consecutively. However, :as will be apparent to those skilled in the art, some of the features of my invention may be vused vin lother systems. `l'cr example, the arrangement of circuits hereinafter disclosed can be adapted to a six unit code by adding the sixth contact ormagnet wherever necessary, and the Achecking signals may remain leaving the counting devices unaltered.

I also `provide means to prevent the recording and re-transmission of more than one such blank or message end signal, such as now occurs with considerable waste of line time. To this end "in the preferred embodiment of my invention I utilize `the iirst blank signal to signify the end of a message and to switch -circuits to the test Vinstruments at both ends of the line. A test imstill further objects of my invention are to' associate in improved manner a counter with each checking transmitter and each checking receiver to register the successive counts; to provide novel means for stopping reception of messages and to operate an alarm signal, if the count numbers at the receiving and sending stations do not check, or if a fault occurs in the circuits or apparatus; and to imprint corresponding numbers on the record medium used for transmission at the sending station and on the received record medium at the receiving station for each message or group of messages in consecutive order. Further objects will become apparent from the following description and claims. Referring now to the drawings: Y Figure 1 is a schematic view illustrating a preferred embodiment of test instrument, counting apparatus and numberingstamp.

' Figure 2 is a sectional view along line A-A of Figure 1. f Figure 3 is a sectional view along line B-B of yFigure 1. vFigure 4 is a schematicv view of the sending tape perforator, transmitter, and numbering stamp at a sending station in the preferred embodiment of my invention. .Figure 5 shows how the count number is irn- `printed on the tape over the perforations at the 'sending station. Figure 6T illustrates the receiving tape passing through theA receiving perforator, numbering stamp andre-transmitter at the receiving and repeating' station. Figure 7 shows a preferred circuitV arrangement of my invention as applied to the transmitting end of asimplex telegraph'system.

'Figure 8 shows a preferred circuit arrangementapplyingmy invention tothe receiving end of a simplex telegraph system. f 1

Figure 9 shows the transmitting and associated flocal segments of a multiplex distributor at the :sending station for use with my invention.

Figure '10 shows the receiving and associated local segments vofa multiplex distributor 'at a receiving station for use with my invention.

Test apparatus 4Referring to Figures l, 2 and 3, in my preferred fembodimentof test instrument, I employ cylinder I having two rows of iive indentations, each .numbered'2 to 6 and each arranged in a spiral ,fover its-cylindrical surface. Cylinder I is fixed to a shaft 8 mounted in suitable bearings not shown. -A lll-toothed ratchet wheel I is fixed to shaft 8. Feed pawl II pivoted on armature lever I2 of .magnet I3 engages ratchet I0 upon energization .fof magnet I3 to turn shaft 8 and parts connected ythereto step by step. Armature lever I2 is held normally retracted by a suitablespring I2. A detent lever I carrying a detent roller I4 is ratchet I0 in the set position. Feed pawl I I when retracted engages pin I6 and is withdrawn from contact with ratchet wheel I0 under inuence of spring I2. A counter I1 is operated by shaft 8 to count the operations of magnet I3.

Shaft 8 drives a bevel gear I8 which meshes with a bevel gear attached to a shaft 2l which advances the printing wheels 22 and 23 of a numbering stamp one digit for each operation of magnet I3. 4Shaft-2| extends to a. suitable knob 24 which the operator may'turn to set and reset the numbering assembly as may be necessary. I

AFive contact fingers numbered 25, 26, 21, 28, and 29 are pressed against the cylinder I by individual springs 3|. These contact fingers drop intothe indentations 2 to 6 of cylinder I in succession as the cylinder is turned by the operation'of magnet I3, lever I2 and pawl II on ratchet I0. In Figure" 2, contact finger 25 is shown moved into indentation 2 and is in contactwith the contact bar 33 common to all of the fingers 25 to 29. Contact fingers 26, 21, 28 and 29 (not shown in Figure 2 but shown in Figure 1) are, in this position of cylinder I, riding on the cylinder face and are in contact with bar 34.

In the transmitting position shown in Figures 4 and 5, tape 35 has been perforated with code perforations comprising a telegraph message by the perforator 36 which may be of any well known construction. Tape passes from the perforator to a transmitter 31 which may also be of any well known construction. Tape 35 then passes through the numbering stamp between numbering wheels 22 and 23 and a print hammer 38 operated by a comparatively slow acting solenoid magnet 4I which, when energized, prints the message number on the underside of the tape.

At the receiving and repeating station of Figure 6, the numbering is the same as Figures 4 and 5 except that the numbering stamp is located in advance of the receiving perforator 36a and prints the number on'the upper side of the tape 35a to distinguish the number of a transmitted message from the' number of a received message. However, different print colors or other means of distinctively recording the numbers may be used to distinguish between transmitted and received messages. Tape 35a then passes through re-transmitter 31a to repeat the messages in well known manner.

Circuit connections Figure 7 shows the circuits set during the transmission of a message. The sending distributor is of the well known Baudot system start-stop type, and transmits a start signal, five permutation code signals, and a stop signal. Code signal segments 5I, 52, 53, 54, and 55 are connected respectively to armature levers 56 of switch relay 51 by wires 58. The upper contacts of armature levers 56 connect by wires 59 to the movable contacts of any well known Y type of Baudot code tape transmitter 6I which is operated by magnet 60. The lower contacts of armature levers 56 connect by wires 62 to conta-ct ngers 25 to 29 of test instrument 63, contact lever 29 only being shown in this view.

Stop segment 64 of distributor 50 is connected through wire 65 and relay 66 to wire 61, positive battery v68 and ground .69. Start segment 10 is connected through Wire 18 to contact bar -1I,

Dressed against ratchet I0 by Spring l5 to hold-A 75 negative battery 12, toground 69. Brush arm to armature 86. Lower contact 81 connects to 10,

the opposite terminal of relay 8|. Transmitter operating magnet 80, and relay 84 are connected in series' from ground to upper contact 88` of relay 18- and to relay 89. Contact:v lever 9-| of relay 18 connects to upper contact 92 vat-rclay 155 93. Armature lever 94 of relay 93 connects. through Wire'94 to contact 95 of relay 85, battery 9|-and ground 96'. Operating coil 91 of relay. 93- is-connected through wirev 91 torcontactbar.

33 and to positive battery 98 and ground I|3,'.m;

Holding coil 99- of relay 93 connects fromV ground4 |00,` battery |88', contacts I8! which. are normally open through wire IOI to contact |02' vat relay 18. Magnet I8 of test instrument 63 is in circuit with norm-ally open grounded contacts |03 and numbering stamp solenoid 4| through wire I 03 to battery |00 and ground |00. Operating coil |04- of relay 51 connects from ground |04' to contact |05 of relay 18 through wire |05". The circuit of holding coil |88 of relay 51' is. from ground |04', coilV |06, contacts |01 which arel normally open, through Wire |01' to contactsfl, battery |09- Iand ground ||0. Relay 89 connects" towre I|| and contact I|2 of relay 93. Contact. bar 31| of test instrument 63 connects to negative battery I|3 and ground II'3 through wire H4. Magnet ||5 and stop lever` IIB are normallyI incl'uded in the mechanism ofthe standard startstop transmitting distributor 50 and when message transmission stops magnet ||5 is energized in Wellknown manner. BoxY I|1v represents the receiving-apparatus at this end of the. duplex line circuit 14.

In the receiving terminal (Figure 8), the circuits lare shown With a message being received. Armature |I8r of receiving relayV |.I9 (in. duplexV line 14) is connected to battery |20'i and ground. Contact |2| of relay |20v is connectedv through Wire |2|l to the start magnet |22Y of start-stop receiving distributor |23, to the ror tating brush arm |24, and to distributor segment |-25. The distributor |23 may be of conventional type wherein brush. arm |24 is frictionally driven and released for a single revolution by theV start signal of each received signalling combinationthrough operation` of start magnet |22. Start magnet |22 may also be the operating magnet of a conventional start-stop printer (not shown) in which case brush arm |24 would be attached tov the selecting shaft of the start-stop printer;l Brushes |25, rotatable with but insulated from` arm |24, normally rest on yand are in contact With segments |25 and |28. Box |29 represents the transmitting apparatus at this distant end of. the" line', similar to the transmitting' apparatus shown' in Figure 1.

The receiving segments |32, |33', |34, |35, and |36 of distributor |23 connect by Wires |31, vrespectively, to contact levers |38 of transfer relay |139; The upper contacts |40 of contact levers |38 each connect through Wires |40" to' perforator punch selecting magnets I4 I' to a common ter-` minal Wire |42, then through operating coil |46 of` relay |411 andV groundV |48. Holding' coil." |49" of relay |41l connects from ground |150 and battacts- |152. oi relayY I 53, contacts |54 of relay |41 torground- |48. Relay |53 is connected through. condenser |-55fby Wire |53' to armature |56- or relay- |51.V Lowerfcontact |58 of relay |51 connects-t0 the opposite terminal of relay |53 through Wire |58. Upper contact |59 of relay |5fIf-is connected. through battery |60, condenser If55ran'd wire. 53. to armature I 58.

Segment` |28.- of vdistributor |23 connects through-.Wire |6| through contact lever |54 of relay |13, andV through wire |64', perforator punch andfeedtmagnet of receiving perforator 38a, and1 relay I51toy ground at |85. Contact/|88` of relayr |41. connects through wire |88 operating coil` I-Il'Iof relay I 39V and relay |88 to ground .|1582V Holding coil |10 of relay |39 connectsfrom. ground |10. through normally open contacts` |.'||l of relay |39 through wire |1I, normally closed contacts |112. oftest relay |13, battery tillY and ground.. |50. test. relay |13 connects tov ground |13 and contact` bar .33' of test. instrument 03 through Wire |142- .Holding coil. I-15,` of relay |13 connects, fromgroundr |50 and'. battery |5| through normally openicontacts .|13, wire |15', normally open contacts. |111. and ground |11. Numbering solenoid.- 4| and. test instrument stepping magnet I3 areconnected in series from ground |18 through wire |19- to. normally open contacts IBI of relay I.'I3,.battery I 5| andground |50.

The lower contacts |82 of contact levers |40 ofA relay |395 are individually connected. by wires' |83 to contact fingers 25 to 29 of the test instrument `83, contact nger 25 only being shown inv this view. Contact bar 34 is 'connected throughwire |84 and relay .|85 to ground |85'. Slow releasev relay |88 is connected through wire |188 from ground |81 through contacts |81 of relay. |188 to. holding coil |18. of relay |39. The circuitfoftroublesignal.relay |88 includes battery |89,normally open contacts |99 of relay |58 `and. I9I.- of-relay |86. Locking and signalling circuit of relay |88is throughbattery |89, normally open contacts. |92'. of relay |88-, Wire |922.- release key |93, and signalapparatus |94. Contacts |95. of relay |88 are included in a circuit from ground |-20',.battery I20through wire |95', to start magnet |22 and ground. Contacts |98 of relay |85 are: includedI in the operating circuit for relay |f8 8i through Vwire |91..

V, Operation-of preferred embodiment Having2 describedl the circuit connections of a preferred test apparatus and a system embodying` my invention during message transmission, I will now describe their operation. It will hoW- ever. beunderstood that theresults to be obtained bythe operation of the described circuits can be had by other circuit, relay and apparatus arrangements Withoutf departing from the invention herein disclosed.

The telegraph message Yis first prepared for transmission at a keyboard transmitter or keyboard perforator 38 in the ,usual manner. -HoW- ever, at the' end of each. message, or group of messages if they are all addressed for delivery at the same city, the operator at the keyboard of a start-stop transmitter adds the message end signali by operating the blank key which transmits` only the start-stop signals but no selecting or marking code'signals or,.if a keyboard perforator is usedl'feedsf out the tape 35 with at least one blanki signal space sothe; tape. will transmit the blank. message: end` signal in passing thrdughy tranismitterfl'.. 1. 1..

Operating coil |14 of' The circuits in Figures 7 and 8 are shownin the normal position for message transmission. In this condition of the system, positive battery 68, Figure '1, is connected to the line 14 through relay y66, stop segment 64 and brush arm 13. Relay E6 is energized and closes a circuit through contacts 95, 92, and 88 to energize relay 84 and transmitter operatingmagnet l6|). Relay 84 closes a circuit through battery 8|' and condenser 85 to charge the latter. Contacts 80 of relay 8| have closed a circuit through holding coil 11 of relay 18 to energize the same. Line relay ||9 at the distant station, Figure 8, closes contacts |2| which close a local circuit from battery |26 to the stop or printer magnet |22, and brush arm |24 is arrested. A circuit from battery |26, contacts |2|, segment |25, brushes |26, segment |28, perforator operating magnet |65 and relay |51 is also closed.

When brush arm 13 (Figure 1) now leaves stop segment 64, relay 66 is de-energized opening contacts 95, and the circuit through relay l84 and transmitter magnet 66 is broken. Transmitter magnet 60 releases its armature to feed the tape in accordance with the normal operation of a standard tape transmitter, and relay 84 opens contacts 83 and closes contacts 81, thus establishing a circuit through relay 8| and condenser 85, which then discharges through relay 8|, operating armature 88, to open the circuit through holding coil 11 of relay 18 releasing armatures 82 and 9|. When brush arm 13 contacts with start segment 10, a negative or spacing impulse is transmitted over line 14 from battery 12 which operates to move contact lever 8 of relay ||9 (Figure 8) away from contact |2| opening the circuit to start magnet |22 which releases the selecting shaft of a normal start-stop printer as Well as brush arm |24. The circuit to perforator operating magnet |65 of perforator 36a (Figure 6) is opened when brushes |26 leave segments |25 and |28, which then operates to feed the receiving tape 35a. The circuit to relay |51 is also opened. Relay |51 While it was energized closed a. circuit through battery |168 and condenser |55 charging the latter. On the de-energization of relay |51, its armature |56 is released to close a circuit through relay |53 and condenser |55 which discharges through relay |53 operating the same to open the circuit through holding coil |49 of relay |41 so that, should relay |41 have been previously operated, it will now be released.

As brush arm 13 (Figure 1) continues to rotate, it will send the code combination of signals for the letter set up on transmitter 6| over the transmitting segments 5|, 52, 53, 54 and 55 in positive and negative impulses. As shown in the setting of the contacts of transmitter 6|, three negative impulses and two positive impulses will be transmitted. The three negative impulses will be sent from ground 69, negative battery 12, upper contacts 55', contact levers 56 of relay 51 to segments 5|, 52 and 53, brush arm 13 and line 14 and operate relay I9 to move its armature away from contact |2|. The two positive impulses will pass from ground, positive battery 68, through operating coil 11 of relay 18, upper contacts 56' of relay 51, contact levers 56 and segments 54 and 55 of distributor 58, brush arm 13 and to line 14. Relay 18 will be operated to close a circuit through its holding coil 11, and will prepare a circuit from contacts 95 (which are now open) of relay 66 through contacts 84 and 92 of relay 93, contacts 9| and 88 of relay 18, relay 84, magnet 60 and to ground. When thereafter brush arm 1.3 contacts "through relay 8|.

with segments 64, the circuit through relay 66 isf closed operating same to close contacts 95. Current will then pass from ground 96 and batteryv 96, contacts 95, contacts 94--92, contacts 9|-88, relay 84, magnet 66 and ground. Magnet 60 Will thereupon operate to feed the tape to position for the next code combination of signals. RelayL 84 will operate to charge condenser 85 as before tures 82 and 9|. to rotate will transmit code combinations of signals to line 14 in the manner previously explained and so long as code combinations comprising at least one marking or positive signal are transmitted this cycle of operation continues. l

At the distant end of line 14, relay 9 (Figure 8) will operate t0 open and close contacts |2| and magnet |22 will be operated to make settings in the start-stop receiving printer in accordance with the received impulses. The impulses received from relay ||9 will also be transmitted to brush arm |24 so that, while the latter is travelling over segments |32 to |36 in unison with the travel of brush arm 13 over the transmitting segments, selecting magnets |4| of perforator 36a will be operated in accordance with the impulses received. According to the setting of tape transmitter 6| as shown in Figure 7, no impulses will be received on segments |32, |33, and |34, but impulses will be received on segments |35 and |36 which pass through the perforator selecting magnets |4| connected thereto and through operating coil |46 of relay |41 and to ground. Relay |41 will be operated to open contacts |66 and |11 and to close contact |54 Which with contacts |52 of relay |53 are included in the circuit of holding coil |49 of relay |41 which therefore remains operated. When brushes |26 reach segments |25 and |28, the normal stop signal will be received from transmitting distributor over line 14 and contacts |2| of relay 9 will be closed. Current will pass from ground |20 and battery |26, contacts 2|, to printer operating or start magnet |22 causing it to arrest brush arm |24 in accordance with the normal operation of a start-stop system.

Current will also pass through brushes |26 from' battery |26, segments |25 and |28, wire |6|, contacts |64 of relay |13, perforator operating magnet |65, relay |51 and ground |65. Magnet |65 will thereupon operate to perforate the tape 35a in accordance with the code signals received on magnets |4|, and relay |51 will operate to charge condenser |55 in the manner previously explained. When brushes |26 leave stop segments |25 and |28, the circuit just described will be opened. Magnet |65 when de-energized will operate to feed the receiving tape 35a. Relay |51 then releases armature |56 to close the circuit through contact |58, relay |53 and condenser |55. Condenser 55 thereupon discharges through relay |53 operating it to open contacts |52 includedin the circuit of holding coil |49 of relay |41 which then releases its contact armatures. This receiving cycle of. operation continues as long as code.

Relay 8| opens the holding circuit to coil 11 of relay 18 which releases arma-y Brush arm 13 as it continuesv `combinations including" 'at least one positive* or fmarking 'signal' are received.

remains unoperatedflwhenbrush arm 13 reaches 'stop ysegment 61|. `ARelay 6'6will beenergize'd to Aclose contacts A95, and an Aimpulse will pass-from ground 96 'and 'batteryf96, contacts l$15, 'contacts Uli- 92 of relay'Sl'S, contacts'I-Il05 of relay 18, operating coil V'-IEH! oiswitch `relay 51 to Aground "I`4.# Switch relay 51"Willoperate t0 move contact levers 56 away from'their upper contacts 55 to their llower contacts, `thus switching thewires transmitter1 -vIi and inl contact with fingers 25 to 29, lrespectively, of test instrument 53 through Wires '62. ASwitclirelay"5"| closes 'the circuit to its 'holding coil H16 throught contacts V| 01 and closed contacts |118 of relay 89;` Contacts |03 of relay 51 close the circuit "for stepping magnet I3 and 4numbering solenoid '41 of the test instrument.

A Stepping magnet |"3f-Will operate the `test instrument to step cylinder "I one step `forward 'so -that 'finger 2'9wi1l be movedout'of indentation-2 and nger2-5 Will'dropiinto indentation '6'. Number- 'ingsol'enoid'liI -Wi-ll'operate lto print a number on the underside ofthetransmitting perforated tape 35 in accordance-with the number Yof the message transmitted.

signal-which proceeds in"thefol1owing manner. As brush 'arm A131 passes 'over/segment 10, it transmits the normal'start-signal-to line 14. Then, as it passes over lsegments V51| to- `55, Yit transmits the test signal.` According -to --the setti-ng -of Athe -test transmitter, 'ingers- 216, "21, 2-8 Vand 29 at -this 'time arein contactwithbar 34 fand/connected to ysegments 54 to 5|, respectively, andas contact --bar 34 is connected `toenegative --battery I I 3 and ground I I3"fnegativeimpulses willl be transmitted from ngers *Z6-to 2e-over line 14. Contactbar 'is'Y (.:omieetedV to operati-ng -coil v 9-1 of"relay9f3, hposi-tivebattery-92|- and groundv I'VI 3 so that when brush arm- 13 Ypasses over segment 551-a -positive test impulse' Vwill be transmitted over line 14 Venergizing relay 93. FWf'henrelay '93 operatesV it -closes a -`circuit through its holding coil-99 irom ground 100, -battery FYI-00', contacts IUI, holding coilf'99, andcontacts |102;8270f relay 18 to ground. Contact armature 94 of relay v*93 is Voperated to 4move away from contact- 924 into engagementwith contact I`|2.

Then when brush Y arm V13 reaches' segmentV 34, `relay 66 is .operatedtocl'ose contacts95 establish- 'ing a'circuit from battery 961'and ground96,fcon 'tacts `94'I|`2', krelay "89,` relayv 84, magnet'llto ground. Relay V89 `Vopens vthe holding circuit' for 'relay 51", releasing, itV and causing 'contact` levers 56 to move away'fromv the lower vcontactsinto engagement with the upper contacts, thus again vconnecting segments 5I to 55 to the contacts of transmitter 6I. Stepping magnet I3 and numbering solenoid '4| of the testtransmitter arer'eleased bythe opening of contacts |03 of relay 51. Magnet'l' .will loperate to feed the trans- .mitting tape v35 aheadthe space of'one code com- "bination, and re1ay'84"will operate to chargecon- 4denser 85. So long as'thegfll'owing-code com- "circuits remain in thisY-condition. When, however, a code combination containinga positive or `markingfsignal reaches transmitter 6I, relay 18 will' be energized in the 4manner previously -explainedf, and the holding circuit through coil 99 oirel-M4313'willioe opened atcontact vI02 Aof "relay A`18, thus restoring the Vrelays and circuits to the normalmessage transmission condition.

Upon reception'ofI a blank orvno character signalatf the distant end of the line, relayA I'IS, after receiving the start signal, does not receive `any positive orv `marking' impulses WhileV 'brush- 'arm 24 passes Aover segments lI 32 r:to |36 and noV Viin- Vpulses-'are transmitted to perforatorrselecting magnets mi and operatingv coil |46, of relay |41, whichiisnot energized; When-brushes P2B-reach segmentsme `and T25, the normal positivestop 'impulse is' received on relay I9 which'closescon- `tract 1121i, Aestablfislring a circuit fromY ground 120 'and battery 20 through" printer magnetifIZZ' to VAground Aand-izhrough*brushesV |26, segments/H5 t28, contacts |511v of relay |13, contacts PS3-+56 off relay |41, operating coil |51 of switch -relay |39, rela-y 16Std-ground |68. 4Switch-re- @to bef noted -thatV relay |68 opens contact-|181 Vbeforecontacts- Y|11 are closed -so Ano impulse `will *and-are operated at sth-11s timer lating `mag-net I65 when energized at-'this time,

binations to be transmittedjgare V,blank signals Y "which contain no marking or`positive signals, the

pass vto relay-|188- Yover wire |85 at -this time.

Receiving periorator `operating magnet -I 65 and relay |51-alsoreceive-an impulse from-batteryl=t20 Perforator' oper- `does-not-i-fngage any punches-since lno positivefor markingsi-gnalshave-been received. The message end. or blank signalis.- therefore .recorded inthe receivingtapef35a, which willbefed forward-the -space of one-code combination when perforator operating magnet |65 -is de..-energized.. Relay |51 operates to charge condenser |55: as.previously explained.v 4This completes the operation atthe receiving;station.` when. a lmessage and blank'V combinationvisl received andthe circuits are `prepared to receive the testsignal. Y

As` previouslylfexplained, they blank `signalfoperated fto .leave `relay 141 `cle-energized i andswitch Vrelay 1I 39.4energized. Then, when theitestrsignals Vcomprising four negativeand. onepositiveimpulses. are transmitted over-line 11|, thenegative `impulses operaterelay v|.|:9 tomove its armature-away from contactl 2 I.. The following-positive. pulse. of z-.the testk signal .willclose contact. |.2| A.whenzbrush arm |.-2:4\is in contact with segment |36", andacircuit will be,establishedfrom'ground |20", battery 12,0', brushzarm |2|,.seg1nentr `131i, .lower contact. ;I^82,;and l,lever 1:33. of relay |33,

` ateyand closea circuit through, its holding-coil :from ground |552, battery I5 I contacts; :|116

test instrument operating magnet I3, niunloering Asolenoid to` ground |18. Magnetl .will operate the test instrumentto stepcylinder I one step forward. Finger v2,-5 will thenrideron face. of cylinder I AAandiinger `2li will drop into Vinclentation23.. `Numbering] solenoid 4I `yvill..inl1

'Il print a number on the upper side of the received through holding coil |15. assumes its normal unoperated position. When thereafter brushes |26 connect segments |25 and tape 35a. Open contacts |12 of relay |13 will open the circuit of holding coil of relay |39, releasing the same, so that contact levers |38 will now be restored to their normal position engaging .their upper contacts |40. Contacts |64 of relay |13 will be opened. When thereafter brushes |26 contact with segments |25 and |28, and relay ||9 receives a positive stop impulse, no current will `pass from battery |20 to perforator magnet |65 `since contacts |64 are open, perforator magnet |65 will not be operated, and the test signal just :received will not be perforated in tape 35a and therefore not recorded. Start magnet |22 Will be operated to arrest the printer selecting shaft and brush arm |24 in the normal manner.

When brush arm |24 is released for the reception of the next character code combination including positive or marking signals, then corresponding impulses will be received over segments |32 to |36, relay |41 will be energized in the manner previously described, and contact |11 will be opened to release relay |13 by opening the circuit Relay |13 thereupon |28, an impulse will be transmitted to perforator operating magnet |65 and relay |56, as previously explained. Relay |41 will be de-energized each .are more than one blank perforations in the transmitting tape, they will be transmitted to the receiving station, but will not be recorded by perforator |65 since no current can pass to perforator operating magnet |65 as long as relay |13 is operated and the contacts |64 remain open.

Should a. line disturbance or any other fault prevent the receiving station receiving consecutive messages, the test instrument 63 at the receiving station will lose synchronism with test instrument 63 at the sending station, and corresponding lingers 25 to 29 of the two instruments will not be in contact with their bars 33 and 34,

-respectively. Then, when a test signal is reand in contact with bar 33 at the receiving station will not correspond with the nger in contact with bar 33 at the sending station. When |86 is slow to release so that, when relay |68 is operated the second time and contacts |9| and are closed, a circuit is established through relay |88 and battery |89. Contacts |92 of relay |88 then close a locking circuit through relay |88 and battery |89, contacts |92, release key contact |93, and signal apparatus |94. Contacts v 51212 also close and connect battery |20 directly to start magnet |22 so that it cannotfbe released when relay ||9 receives a start or negative inpulse and, therefore, further signal combinations will not be recorded.

Signal apparatus |94 operates at thisv timeto call in an attendant to correct any fault in the circuit or apparatus. Release key |93 when depressed will stop the operation of an alarm |94 by opening the holding circuit of relay |88. Since each message at the sendingr station and each properly received message at the receiving station are numbered by corresponding number imprints on the transmitting and receiving tapes 35 and 35a, it will be easy for the maintenance men to re-adju'st transmission in the proper order so that no messages will be lost. Transmission is resumed after maintenance men at transmitting and receiving stations communicate with each other to correct the fault, identify the number of the last properly received message stamped on tape 35a, set the test instrumentsin corrected positions, and thereafter re-transmit messages which have not been received.

If for any reason a combination of impulses other than the correct test signal should be received after a blank signal, some ofthe contact fingers 25 to 29 at the receiving station will be in contact with contact bar 34. Then one or more impulses will be transmitted to relay |85 as well as to relay |13. If relay |85 is operated at any time, it operates contacts |96 to close circuit through battery |89, relay |88 and alarm apparatus |96. Relay |88 thereupon locks up, the alarm is given, and start magnet |22 is also energized as previously explained so that reception and re-transmission by re-transmitter 31a stops until the fault is corrected.

If the receiving apparatus is not started properly on the reception of a start signal on start magnet |22, or is otherwise out of order, relay |39 will receive several impulses in succession over contact |64 of relay |13 and contact |11 of relay |41. From previous explanation it will be noted that the second impulse on relay |39 then operates relay |68 after slow relay |86 has been operated. This closes the circuit through contacts |90, |9|, relay |88 and battery |89 and operates relay 88 to start the alarm |94.

The alarm |94 will also normally be operated if the receiving distributor does not operate in synchronism with the sending distributor or if the circuits are out of order, for under such conditions it Vis very unlikely that the test signal will be properly received.

If one or more blank signal combinations are received in the body of a message, the first blank `combination will switch the circuits of receiving kalarm apparatus to operate for the reason that the receiving test instrument will not be in synchronism with the received test signal, or one'or more impulses will be received on contact bar 34 of the receiving test instrument.

It will be noted that the received test signal is not recorded with the received message in' the Multiplex system The system of circuits so far described maybe applied to a multiplex system forv transmitting andreceiving messages asillustrated in Figures -9. and 10.

In this form of my invention threegroupsof distributor segments 5| to,55 of a three channel multiplex distributor arev each connected through conductors 58 to contact levers 56 of a. .relayv 5l .as illustrated in Figure '7. The .groups of segments to 555 are connected successively by :brush to contact ring. 202. which inturn is connected to line 'i4 through conductor. 1.4' and .une relay '[5 as illustrated in Figure '7, IalSO replace relay 6.6 and segmented. of Figure 7. with ,a distributor ring havinga segment 2 0,3 for each channel to which three conductors 94, .areconknested and whichin turn lconnect `directly to. centact finger 94 of relay |33l in Figure 7. A brush` 20,4 rotating in unison with brush 20| connects. the segments 203 at preneriy,A timed intervals te con 'ducting ring 205 which in turn is connected to battery 9 6 and ground 06' illustrated in Figure?. 'In ,like manner at the, receiving endl three groups 0f receiving segments l,32 to |35 of a three channel multiplex receiving distributor are individually connected by wires |31 te idiesentact levers |38-r of three relays |39as illustratedin Figure 8. Brush 2.06 connects these segments successively t0 common ring 20'! which in tui-nA is connected to contact 12| of receiving relay ||9 and battery |204 to ground |20 through conductorl I2!" illustrated in Figure 8, Local or, `as

usually termed, sixth pulse, segments 2.1115vv are .connected through wires ISI t0. contacts LGA of three relays |13 connected as illustratedin Figure 8. Contacts |95 of relays lsconlnected as in Figure 8 are connected through` wire..|9,5 and Astart magnet |22 of Yl1"igure 8,is, eliminated.v Contacts |95 will operate to closela circuit when a fault occurs to put positive battery 209-v from ground 2 I0 on perforating operating magnet, |65 as, shown. Battery 209 is alsoconnectedtoring 2| ofthe receiving distributor whichinturn is connected by brush 2|2 rotatingin unison with brush 206 to local pulse distributor segments 2001.

The transmitting andV receiving distributors aremaintained in synchronism intany well known manner and, as will be understood by those versed in the art, certain parts and connections normally associated only with a startstop system Vfor maintaining synchronism. whichlare shown in Figures 7 and 8, "such asstart. magnet -the alarm operated as above.

;tions offfbrush `arm |24 and brushes |26 ofvFi-g'- ure 8.

. If, dueto line or apparatus failure, no positive or marking vimpulses are received on relay. H9 and .contacts .|2I` remain open, brushes 2|2 -will `contact-with segments 208 and ring 2| (Figure 10.) several times in succession and if this `occurs at any time other than during the reception of blank code combinations following the reception of a test code combination, relay 4|39 will receive several impulses in succession and The remaining individual channel equipment associated with the `transmitting and receiving `distributors and not shown in Figures Qand 10 is similar tothat illustratedin Figures 7- and 8 and willbelunderstood by those skilled inthe art -from the description thereofF hereinbefore given in connec-V .tionl with Figures '7` and 8.

1 The invention mayv be embodied in other specii'lc .forms without departing fromV the spi-rit orU essential characteristics thereof. The present embodiment` is therefore to be considered in all respects asillustrative and not restrictive, the scope of the kinvention being indicated by the appendedclaims rather than by the foregoing description, and all changes which come-within the meaning and` rangeV of equivalency of the claims are therefore. intended to be embraced therein.

vWhat is claimed and desired to be secured-by UnitedStates Letters Patent is:

1. A system for. transmitting4 and receiving telegraph messages comprisingmessage transmitting. apparatus; testssignal transmitting apparatus; means associated with said message transmitting` apparatus to conditionsaid test signal apparatus to transmitv different combinations offsignal impulses each-including a positive test signal at. intervals between messages; message receiving apparatus; test signal receiving apparatus interconnected in the line circuit with said test signal transmitting apparatus; circuits associated. withsaidmessage receiving apparatus and. set at the end of a message to receive a test signal; means to compare said set circuits With the. position of #said received test` signal, and means. to stop the further reception of messages whenthe received testsignal does not correspond with the setting of the test signal circuits at the receiving apparatus.

"2. In a telegraph system, means for transmitting message signals and special signal com-- binations to indicate the end of a message; receiving means for said message signals; means under. the control of said receiving means'itor detecting andrecording said message and message endsignals; and means rendered operative in response `to the reception of 'consecutively transmitted message end signals to prevent the duplicaterecording of said signals.

3; A system for transmitting and receiving telegraph messages comprising automatically operated meansfor transmitting message signals and a message endl signal between messages; receiving apparatus for recording received mesf sages; `means associated with said receiving-apparatus to detect and recordsaid message end signal; means responsively controlled by said message end signal controlling operation offthe message recording apparatus to stop the recordjof Ysaid messages and to condition the recordjing meanstto recorda subsequently received code V combination; and further means responsively controlled by `the subsequently received" code combination to restore saidmessage recording apparatus to operative condition.

4. A system for transmitting and receiving telegraph messages in permutation code comprising message and message end signal transmitting apparatus; message receiving apparatus; means associated with said transmitting apparatus to detect a message end signal and thereupon stop the transmission of telegraph messages and start the transmission of a test signal code combination consisting of one marking signal and four spacing signals; means to progressively change the relation of the marking signal to the spacing signals in successive test signal code combinations; and additional means to render the transmitting apparatus effective forl the resumplltion of transmission of telegraph messages after a test code combination has been transmitted.

5. A system for transmitting and receiving telegraph messages embodying message transmitting apparatus for transmitting message code combinations of marking and spacing signals and a message end signal code combination; test signal transmitting apparatus operative in response to said message yend signal to transmit one of a series of differing test signal code combinations, each consisting of one marking signal and a plurality of spacing signals, said marking signals being transmitted in progressive succession with relation to said spacing signals; message receiving apparatus; test signal receiving apparatus associated with said message receiving apparatus; means to successively and progressively set said test signal receiving apparatus after the reception of each message end signal code combination; means associated with said test signal receiving apparatus to receive and compare the received test signal code combination with the progressive setting of said test signal receiving apparatus; means for conditioning said message receiving apparatus to permit continued reception of message signals if the received test signal code combination corresponds with the progressive setting of said test signal receiving apparatus; and means operatively controlling said conditioning means to stop the reception of said message signals if said received test signal code combination does not correspond with the setting of said test signal receiving apparatus.

6. In a telegraph system, message andmessage end signal transmitting apparatus; means responsive to a message end signal for transmitting a test signal; receiving apparatus responsive to said message and message end signals including means to record the received message and message end signal in a record medium to be used for retransmitting said signals; means to receive said test signal; means under control of said test signal receiving means for controlling the operation of said message and message end signal receiving apparatus and additional means to render the recording means inoperative to record said test signal in said record medium.

7. A system for transmitting and receiving groups of signal combinations; signal transmitting apparatus; signal receiving apparatus; a line circuit connecting said transmitting and receiving apparatus; said signal receiving apparatus including a record medium used for the purpose of retransmitting received groups of signal combinations to a succeeding line circuit; means for transmitting a test signal at intervals between transmitted groups of signal combinations; means for receiving said test signal; means under control of the signal receiving apparatus and 16. responsive to the reception of a test signal ,to prevent the recording of said test signal inthe record medium. v

8. In a system of telegraphic communication having message transmission and receiving apparatus connected over a line circuit; test signal transmitting and receiving apparatus connected in said line circuit, means automatically responsive only to the reception of a complete message and message end signal by said message receiving apparatus to establish a test signal'receiving circuit'between said test signal transmitting and receiving apparatus, and means automatically responsive to any one of a plurality of abnormal message or test signal transmitting conditions to disable said message receiving apparatus.

9. In a system of telegraphic communication having message transmission and receiving apparatus connected over a line circuit; test signal transmitting and receiving apparatus connected in said line circuit, means automatically responsive only to the reception of a complete message and message end signal by said message receiving apparatus to establish a test signal receiving circuit between said test signal transmitting and receiving apparatus, means automatically responsive to any one of a plurality of abnormal message or test signal transmitting conditions to disable said message receiving apparatus, and means responsive to a subsequently transmitted combination of message signals to restore said message receiving apparatus to operative condition.

10. In a method of detecting faults in the transmission of telegraph messages between sending and receiving stations, establishing a test signal transmission circuit and transmitting a test signal between said Astations in response to the transmission of each message and message end signal, and conditioning the message receiving apparatus in response to improper reception of said test signal to discontinue further message reception.

11.v In a system of telegraphic communication having message transmitting and receiving apparatus connected over a line circuit; test signal transmitting apparatus connected with the message transmitting apparatus and operatively controlled thereby, test signal receiving apparatus connected with the message receiving apparatus and operatively controlled thereby, and means for interconnecting the test signal transmitting Vand receiving apparatus in the line circuit connections between the message transmitting and receiving apparatus, automatically responsive to the reception of a complete message and message end signal by said message receiving apparatus, to establish circuits for transmitting to the signal receiving apparatus a plurality of different combinations of test signal impulses in periodic succession between the reception of said messager end signal and the reception of a succeeding message.

12. In a telegraph system, two stations, a circuit connecting said two stations, means at one of said stations controlled by forms carrying code markings to transmit signals, means at the other of said stations controlled by said signals to make a record on record receiving material, a number stamp having indications at each of said stations associated with the record material at that station, means to operate each stamp once for each message, means operative during predetermined ones of the intervals between messages to interrupt the message transmission, and means operative during an interruption to transmit signals to compare the indications.

13. Telegraph apparatus for automatically checking Vconsecutive designations of messages represented by code combinations accompanying the messages and arranged in predetermined sequence, comprising a communication channel over which the messages arrive, an instrumentality, means for preventing the instrumentality from operating in case the message designations are received in the predetermined sequence represented by their designations, and other instrumentalities controlled by message designating codes occurring out of the predetermined sequence for causing the instrumentality to' operate.

14. An arrangement for verifying the receipt in numerical order of code messages consecutively numbered which messages arrive over a channel of transmission, comprising, in association With said channel, a stepping device initially settable in accordance With a first number, means for comparing the rst number as received with the position of the stepping device, and means controlled incident to the receipt of each message for stepping the stepping device forward to the next consecutive number.

15. In a system of telegraphic communication, a transmitting station, a receiving station, means at said transmitting station for generating permutation code signals at predetermined intervals, means at said receiving station for establishing identical code signal conditions concurrently with butindependently of those at said transmitting station, and a comparison apparatus including alarm means for responding to any diierences in the composition of said code signals at said transmitting and receiving stations.

16. In a telegraph system, a signaling circuit, similar code signal control devices at terminals of said circuit, a sensing device at each of said terminals to sense the codes presented in effective position by said code signal control device, and means controlled locally as Well as over said circuit to simultaneously advance both said code signal control devices to variable code settings.

17. In a communication system, an arrangement for verifying the receipt in numerical order of sequentially numbered messages transmitted over a channel of transmission, comprising, in association with said channel, means for transmittingy codes indicative of the sequential order of said messages, means for receiving said codes, means for testing said codes for sequential order. and means for indicating failures of said testing means to find sequential order of said codes.

EDWARD E. KLEINSCHMIDT.

REFERENCES CITED The following references are of record in the le of this patent: 

